CHELAN, Wash. — Firefighters held their ground Wednesday, keeping a wildfire from destroying any structures near Chelan in north-central Washington while hoping to make gains with the promise of favorable weather.

More than 120 homes were initially threatened by the fire sparked by lightning Tuesday night in the Union Valley area.

By late Wednesday, "that threat has been much reduced," said Nick Mickel, a public information officer for the fire management team assigned to the blaze. About 80 residents had earlier been told to leave their homes, but that mandatory evacuation notice was eased.

No structures had burned and the only reported injury was a bee sting to a firefighter, Mickel said. The fire has covered about one square mile and was reported to be 20 percent contained.

Fire crews planned to work through the night, patrolling and doing fire line construction and mopup, Mickel said.

The Red Cross initially opened a shelter at Chelan High School then moved it to a local church, but no one was there.

The Pacific Northwest has been enduring a heat streak for days, with temperatures breaking the 100-degree mark. Some large timber companies halted operations because of the extreme conditions.

Lightning storms have swept through the region, sparking numerous wildfires. About 1,000 lightning strikes were reported in eastern Washington during a six-hour period Tuesday.

Forecasters predicted a reduced chance of thunderstorms and lightning for Thursday.

The number of fires reported on state and private land in Washington this summer has increased by one-third, to about 700 fires, according to the state Department of Natural Resources. Still, far fewer acres have burned than in an average year.

The coming weeks could provide the biggest test of the year, Commissioner of Public Lands Peter Goldmark said in a statement.

Nearly 200 firefighters were on the scene near Chelan. County commissioners declared an emergency, and the Federal Emergency Management Agency authorized federal money to help pay for the firefighting effort.

Kathy Polley, a veterinarian, headed into town to check a sick horse and planned a quick return home.

"Last night I was dreadfully worried," she told The Wenatchee World. "I could see the orange glow just at the top of this hill — and it must have been 200 feet high."

Mike McCoy had a low-key attitude about the fire.

"We've been through this so many times, I'm not worried about it," he told the newspaper. "We know just what to grab."

In the Okanogan-Wenatchee National Forest, lightning storms ignited 22 mostly small fires late Tuesday. A dozen new fires were reported Wednesday as conditions became hotter and drier, said Robin DeMario, Forest Service spokeswoman.

None of the fires were threatening structures.

West of the Cascades, firefighters blamed a lit cigarette for a fire in the Interstate 5 median that temporarily backed up traffic for miles in the suburbs south of Seattle.

In the Spokane area, a small, six-acre brush fire near Arbor Crest Winery was surrounded by bulldozer lines and firefighters were mopping up the blaze.

Firefighters also reached 90 percent containment of several fires burning on the Colville Indian Reservation northeast of Nespelem. The fires have burned 955 acres.

A fire burning near the popular fly-fishing section of the North Umpqua River in southwestern Oregon grew to 1,630 acres, and the Forest Service said smoke in the air had grounded helicopters and air tankers called in to fight it.

Umpqua National Forest spokeswoman Debra Gray said there were no evacuations in the sparsely populated area about 30 miles east of Roseburg, but state Highway 138 remained closed between Susan Creek Campground and Steamboat Inn.

In central Oregon, more than 400 firefighters continued to battle the Cougar Creek fire, about 10 miles south of John Day in the Strawberry Mountain Wilderness Area. No structures were threatened, but some trails were closed.

The fire has burned about 800 acres, or more than 1 square mile. It was 35 percent contained.